SM840001KATR [MICREL]
106.25MHz Ultra-Low Jitter Clock Synthesizer; 106.25MHz超低抖动时钟合成器
| 型号： | SM840001KATR |
| 厂家： | 
MICREL SEMICONDUCTOR |
| 描述： | 106.25MHz Ultra-Low Jitter Clock Synthesizer |
| 文件： | 总8页 (文件大小：308K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SM840001
106.25MHz Ultra-Low Jitter Clock
Synthesizer
General Description
Features
The SM840001 synthesizer series were designed for Fibre
Channel applications. The device design is optimized for
• Generates a single LVCMOS/LVTTL output
• Integrated loop filter components
• RMS Phase Jitter:
106.25MHz or 212.5MHz using
a
26.5625MHz
fundamental parallel resonant crystal, with stability and
accuracy over the full operating range. The SM840001
includes a unique power reduction methodology, along
with a patented RotaryWaveTM architecture, that provides
a stable clock with very low noise for optimized
performance. This yields an overall improved Bit Error
Rate (BER) and improved waveform integrity.
-
-
510 fs (typ) at 106.25MHz
320 fs (typ) at 212.50MHz
• Operates with either a 3.3V or 2.5V supply
• Power consumption is <77mA @ 3.3 V
• Fundamental crystal oscillator interface
• Input frequency of 26.5625 MHz parallel resonant
• Selectable output frequency: 106.25MHz or 212.5MHz
• Temperature range: –40°C to +75°C
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
• Available in 8-pin TSSOP package
Applications
• Fibre Channel
• Storage
___________________________________________________________________________________________________________
Block Diagram
RotaryWave is a trademark of Multigig, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
Micrel, Inc.
SM840001
Ordering Information(1)
Part Number
Package
Type
Operating Range
Package Marking
Lead Finish
SM840001KA
SM840001KA TR(2)
Note:
K-8
K-8
-40°C to +75°C
-40°C to +75°C
840001
840001
NiPdAu
NiPdAu
1. Devices are Green, RoHS-compliant and PFOS-compliant.
2. Tape and Reel.
Pin Configuration
8-Pin TSSOP (K-8)
Pin Description
Pin Number
Pin Name
VDDA
OE
Type
Level
Pin Function
Analog Power.
1
2
3
4
5
6
7
8
P
I
Pull-up
Output Enable: 1 = Enable, 0 = Disable.
Crystal Out.
XTAL OUT
XTAL IN
FSEL
O
I
Crystal Input.
I
Pull-down
Frequency Select Pin.
Ground.
GND
P
O
P
Q0
Single Ended LVCMOS Clock Out.
Core Power.
VDD
Frequency Select Table
FSEL
Output (MHz)
0
1
106.25 (Default)
212.5
Output Enable
OE
0
Output
Disable
Enable
1
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
2
Micrel, Inc.
SM840001
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VDD)...................................................+4.6V
Input Voltage (VIN)................................ –0.50V to VDD+0.5V
Output Voltage (VOUT) .......................... –0.50V to VDD+0.5V
Lead Temperature (soldering, 20sec.)....................... 260°C
Storage Temperature (Ts) .........................–65°C to +150°C
Supply Voltage (VIN)............................. +2.375V to +3.465V
Ambient Temperature (TA) ..........................–40°C to +75°C
Junction Thermal Resistance
TSSOP (θJA).....................................................150°C/W
DC Electrical Characteristics
VDD = 2.5V ±5%; TA = –40°C to +75°C, unless noted.
Symbol
VDD
Parameter
Core Supply Voltage
Analog Supply Voltage
Core Supply Current
Analog Supply Current
Condition
Min
Typ
2.50
2.50
12
Max
2.625
2.625
20
Units
V
2.375
2.375
VDDA
IDD
V
No load
mA
mA
IDDA
48
55
DC Electrical Characteristics
VDD = 3.3V ±5%; TA = -40°C to +75°C, unless noted.
Symbol
Parameter
Condition
Min
Typ
3.30
3.30
15
Max
3.465
3.465
22
Units
V
VDD
VDDA
IDD
Core Supply Voltage
Analog Supply Voltage
Core Supply Current
Analog Supply Current
3.135
3.135
V
No load
mA
mA
IDDA
49
55
LVCMOS DC Characteristics
VDD = 2.5V and 3.3V ±5%; TA = -40°C to +75°C, unless noted.
Symbol
Parameter
Condition
Min
2
Typ
Max
VDD +0.3
VDD + 0.3
0.80
Units
V
VDD = 3.3V ±5%
VDD = 2.5V ±5%
VDD = 3.3V ±5%
VDD = 2.5V ±5%
VDD = 3.3V ±5%
VDD = 2.5V ±5%
VIH
Input HIGH Voltage
1.7
V
-0.30
-0.30
2.6
V
VIL
Input LOW Voltage
0.70
V
V
VOH
Output HIGH Voltage
1.8
V
VOL
IIH
Output LOW Voltage
Input HIGH Current
Input LOW Current
Input HIGH Current
Input LOW Current
0.5
5
V
Output Enable input
Output Enable input
FSEL input
µA
µA
µA
µA
IIL
-150
-5
IIH
150
IIL
FSEL input
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
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Micrel, Inc.
SM840001
AC Electrical Characteristics
VDD = 2.5V and 3.3V ±5%; TA = -40°C to +75°C, unless noted.
Symbol
Parameter
Condition
Min
Typ
Max
Units
MHz
MHz
FSEL=1
186.66
93.33
212.5
106.25
226.66
113.33
FOUT
Output Frequency
FSEL=0
106.25MHz,
510
320
fs
fs
Integration Range: 637kHz to 10MHz
212.50MHz
tJITTER
RMS Phase Jitter
Integration Range: 2.55MHz to 20MHz
20% to 80%
tR / tF
ODC
Output Rise/Fall Time
Output Duty Cycle
100
48
350
52
ps
%
%
106.25MHz
212.50MHz
45
55
3.3V Carrier Frequency, 106.25MHz
3.3V Carrier Frequency, 212.5MHz
Offset from Carrier
100Hz
Measured Phase Noise
Unit
Offset from Carrier
100Hz
Measured Phase Noise
Unit
-97
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
-92
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
1kHz
-122
-131
-126
-144
-163
-165
1kHz
-116
-124
-120
-138
-161
-163
10kHz
10kHz
100kHz
1MHz
100kHz
1MHz
10MHz
10MHz
40MHz
40MHz
Crystal Characteristics
Parameter
Condition
Min
Typ
Max
Units
Mode of Oscillation
Frequency
Fundamental Parallel Resonant
26.5625
MHz
Ω
Equivalent Series Resistance (ESR)
Shunt Capacitor
Drive Level
50
7
pF
1
mW
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
4
Micrel, Inc.
SM840001
Functional Description
The SM840001 provides a high performance and high
accuracy solution for a precision clock source at 106.25
or 212.50MHz derived from a low cost 26.5625MHz Xtal.
A single 12mA LVCMOS output is provided with tri state
capability, controlled via an external pin (OE).
ratios. Output Divider ratios are fixed at either ÷15 or ÷30
controlled via the FSEL pin, and the feedback divider
also fixed at ÷120. Duty Cycle is inherently improved and
guarantees tight control and stability on this critical
specification. The provides improved specifications for
Duty Cycle, Jitter, Phase Noise, Power Consumption,
and noise sensitivity. Additionally, the SM840001 will
operate at either 3.3V or 2.5V supplies.
The design of the SM840001 consumes very low power
in the PLL due to a patented technology in the VCO and
the associated dividers. The VCO range is ~3.2GHz to
3.5GHz providing high resolution and easy integer divide
Switching Waveforms
RMS Phase Noise/Jitter
Phase Noise Plot: 212.5MHz @ 3.3V
Phase Noise Plot: 106.25MHz @ 3.3V
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
5
Micrel, Inc.
SM840001
Power Supply Filtering
Crystal Loading
The SM840001 provides separate power supply pins to
isolate any high switching noise from outputs to internal
core blocks. VDD and VDDA should be individually
connected to the power plane through vias. Bypass
capacitors should be used for each pin. Figure 2
illustrates how the power supply filter for 3.3V and 2.5V
is configured.
Crystal Recommendations
This device requires a parallel resonance crystal.
Substituting a series resonance crystal will cause this
device to operate at the wrong frequency and violate the
ppm specifications.
To achieve low ppm error, the total capacitance of the
crystal must be considered in order to calculate
appropriate capacitive loading (CL).
Load Capacitance at each side: Trim Capacitance = Ct =
(2*CL-(Cb + Cd))
CL: Crystal load capacitance. Defined by manufacturer
Ct: External trim capacitors. (Trimmed CL Load
capacitance to get the right ppm)
Cb: Board capacitance (vias, traces, etc.)
Cd: Internal capacitance of the device (lead frame, bond
wires, pin, etc.)
Equivalent Series
Resistance (ESR)
Max.
Cut
Load
Cap.
Shunt
Cap.
Max.
Drive
Max.
Figure 2.
50Ω
AT
18pF
7pF
0.1m
W
Crystal Input Interface
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
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Micrel, Inc.
SM840001
Total capacitance seen by crystal = CL =
1
Example:
CL = 18pF, Cb = 2pF, Cd = 4pF
Trim Cap = Ct = 2 (18pF) - (2pF +4pF) = 30pF
The SM843022 has been characterized with 25MHz,
18pF parallel resonant crystal. The trim capacitors Ct1
and Ct2 were optimized to minimize the ppm error.
1
+
1
To minimize the board capacitance, a short trace from
pin to crystal footprint without vias is desirable. It is
preferable to have ground shielding or distance between
the crystal traces and noisy signals on the board.
(Ct1 + Cb1 + Cd1)
(Ct2 + Cb2 + Cd2)
Board Layout
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
7
Micrel, Inc.
SM840001
Package Information
8-Pin TSSOP (K-8)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its
use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant
into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2010 Micrel, Incorporated.
M9999-031810-B
hbwhelp@micrel.com or (408) 955-1690
March 2010
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